Piston.



No. 736,735. PATENTED AUG. 18, 1903. J. G. JUNKIN.

PISTON.

APPLICATION FILED MAR. 2a. 1903.

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UNITED STATES Patented August 18, 1QO3.

PATENT EEicE.

JOHN C. .IUNKIN, OF GRAFTON, NORTH DAKOTA.

PISTON.

SPECIFICATION formingpart of Letters Patent No. 736,735, dated. August 18, 1903. Application filed March 28, 1903. Serial No. 149,971. (No model.)

To aZZ whom, it may concern:

Be it known that I, JOHN C. JUNKIN, a subject of the King of Great Britain, and a resident of Grafton, in the county of \Valsh and State of North Dakota, have invented anew and Improved Piston, of which the following is a full, clear, and exact description.

The invention relates to horizontal engines and pumps; and its object is to provide a new and improved piston arranged to sustain its own weight in the cylinder by the use of a fluid under constant pressure, so that the friction incident to the piston reciprocating in the cylinder is reduced to a minimum and the cylinder is prevented from wearing oval and causing leakage of steam, water, or other fluid from one side of the piston to the other.

The invention consists of novel features and parts and combinations of the same, as will be more fully described hereinafter and then pointed out in the appended claims.

A practical embodiment of the invention is represented in the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in both views.

Figure l is a sectional side elevation of the improvement as applied, and Fig. 2 is an enlarged transverse section of the same.

In the horizontal cylinder A is mounted to reciprocate a piston-head 13, provided with a piston-rod 0, connected at its outer end in the usual manner with the power-transmitting parts of the engine, and in the lower portion of the said piston-head B is arranged a pressure-chamber D, opening at its lower end onto the peripheral face of the piston-head B at the bottom thereof, and the upper end of the said pressure-chamber D is connected by a port a, with a passage b, extending lengthwise in the piston-rod 0, so that a fluid under pressure can pass by way of the passage 1) and port a into the pressure-chamber D to press against the top thereof, and thereby sustain the weight of the piston in the cylinder A.

The passage 1) is connected at the outer end of the piston-rod C by a flexible connection with a fluid-pressure supply-such as steam, compressed air, or the like-and the pressure supplied by Way of the passage 1) and port a to the pressure-chamber D is maintained constant by a suitable reducing-valve or the like, and the pressure is about equal to the weight of the piston B, so that the latter is floatingly suspended in the cylinder A, and hence the wear of the piston B and cylinder "A is reduced to a minimum.

In order to prevent escape of the fluid from the pressure-chamber D, the latter is provided with a sleeve E, having a packing-ring F and an enlarged lower portion E adjacent to a vent-groove 0, formed in the piston-head and leading to the peripheral face thereof to lessen the pressure per square inch on the bottom of the cylinder. Now by the arrangement described the pressure on the top edge of the sleeve E will force the same downward for the outer end to engage the cylinder, so that the pressure cannot escape from the pressure-chamber to either face of the piston.

The sleeve E is also pressed on onthe top edge by springs G, secured to the pressure-chamber, as plainly indicated in the drawings.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. In a piston, a hollow piston-rod adapted to be connected with a pressure-supply, and a piston-head to which the piston-rod is secured, said head having a pressure-chamber in its periphery and a port leading from the inner end of the chamber to the bore of the piston-rod, as-set forth.

2. In a piston, a piston-head provided with a pressure-chamber in its periphery, means for supplying the chamber with a fluid under pressure, and a sleeve in the said chamber and adapted to be forced outward by pressure, as set forth.

3. A piston having a piston-head provided in its lower portion with a pressure-chamber opening onto the peripheral face of the piston, a hollow piston-rod connected with a pressure-supply and in communication with the upper end of the said pressure-chamber, and a spring-pressed sleeve fitted in the said pressure-chamber and in contact at-its lower end with the cylinder, as set forth.

4. An engine or pump having a horizontal cylinder, a piston-head mounted to reciprocate in the said cylinder and provided with a pressure-chamber in its lower portion, the

bottom of the said pressure-chamber opening onto the bottom of the said cylinder, a hollow piston-rod connected with a pressuresupply and in communication with the said chamber, to supply the latter with a fluid under constant pressure, and a spring-pressed sleeve, fitted in the said pressure-chamber and in contact at its lower end with the said cylinder, as set forth.

5. A piston having a piston-head provided in its lower portion with a pressure-chamber, means for supplying the pressure-chamber with a fluid under constant pressure, a sleeve in the said pressure-chamber and having an enlarged bottom end adjacent to a ventgroove in the piston-head, to lessen the pressure per square inch on the bottom of the cylinder in which the piston reciprocates, as set forth.

6. In a piston, a hollow piston-rod adapted to be connected with a pressure-supply, a piston-head provided with a pressure-chamber in its periphery, and with a port leading from the said chamber to the bore of the pistonrod, andasleeve fitting in the pressure-chamber and adapted to be forced outward by pressure, as and for the purpose set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN G. JUNKIN.

Witnesses:

T. D. OAsEY, HENRIETTA NELSON. 

